The use of spiked shaker head styled fruit harvesters is known in the art as illustrated by way of example with reference to U.S. Pat. No. 4,860,529 to Peterson et al. for "Shaking Mechanism For Fruit Harvesting" and U.S. Pat. No. 4,329,836 to Scudder for "Harvesting Units." However, problems using such spiked shaker head harvesting mechanisms include shaker head diameters being too small to sufficiently penetrate the canopy of a larger fruit bearing trees, especially those found in the citrus field. Further, simply increasing the diameter of the shaker head lowers the natural frequency of the finger elements which reduces the efficiency with which fruit can be shaken loose from their branches, and increases damage thereto. The diameter may be increased to offset the frequency problem, but the diameter would have to be exponentially increased to an impractical length. The harvester will be too big, too long, too wide and awkward to maneuver in a typical grove. Further, if the harvester were high enough to pick tall trees, its height would be too high for transporting, as limited by the DOT specifications for height of equipment traveling on highways. There is a need for a practical way to easily extend the spiked shaker heads and lower them for transport.
Dual shaker head systems are typically used in place of single shaker head systems to provide adequate balancing of the harvester during the oscillating or shaking movement of the shaker head. When inertia of the fruit is used to sever its connection to the fruit stem, the frequency must be of a high enough order of magnitude to generate the required forces to sever this connection. The frequency of a tree nicking action can be reduced when the shaker head displacement (amplitude) is increased. The benefit of a lower frequency provides for reduced damage to the tree, reduced stresses in harvester machine parts, increased durability, and reduced weight. Further, typical shaker head styled harvesters are typically rigid and long, and as such cannot be moved sideways to increase or decrease the penetration depth into the canopy. The rigid machine cannot get close enough to the scallop pockets between two adjacent trees in order to pick the fruit.
As described in the Peterson '529 patent, The spiked head shaker is preferred over other styled harvesters because the spikes, finger elements, can gently enter the fruiting canopy as the harvester moves along the tree rows, and the force of oscillation adjusted to shake ripe fruit loose from the branches without damaging the tree. However, there are inherent disadvantages of shaking a fruit tree with a pivoting, angular, and non-uniform displacement of the spikes. By way of example, a uniform movement having a pivot point off set in relation to the center of the shaker head imparts an angular movement although on a bigger radius, and consequently the tips of the spikes of the shaker head are displaced more than the center of the shaker head. Typically, the tip would have a 6 inch displacement and the center of the shaker head only 3 inch displacement. Therefore, the tips are more aggressively shaking the branches than the center of the shaker head. This results in an extremely aggressive movement of the tips while the central part of the shaker head is not aggressive enough to remove fruit. There is a need for a more uniform translation or movement along the length of the spikes rather than the typical angular displacement which results in the differing linear displacement along the shaking members. Further, it is believed that a single shaker head harvester has the ability to remove fruit as efficiently as a double shaker head machine, but there is a need for improved balancing of a single shaker head harvester.
It is typical for a fruit harvester to operate with a catcher floor adapter to straddle and travel along a row of plants, as described, by way of example, in U.S. Pat. No. 3,772,866 to Sell, for "Apparatus For Harvesting Grapes." Integrating the fruit shaker with a collector comes with some disadvantages, and as a result, a collector operated independently from the shaker is desirable. By way of example, maneuvering the harvester becomes easier, especially with harvesters having a three point mounted system for the shaker, and harvesters typically drawn by the same tractor that operates with the collector. There is a need for a collector to have versatility when negotiating tight turning radii, to have adjustment capability for horizontal and vertical movement that would enable it to be effectively positioned under the tree to catch and convey the fruit.
Further, when using left and right handed collectors in combination, there is a need for a continuous seal therebetween that enables the harvester to intercept and catch the fruit falling from the tree without losing fruit as the harvester moves along and brushes by the trees being harvested. It would further be desirable for the collector to separate debris from fruit before being discharged for transporting of the fruit.